Something about "no style" and your description doesn't make sense to me.

Styles expect the number of images that they were designed with and odd things can happen with more or fewer. It is possible to go in and edit the result to get rid of the 4th slot but a fair number of adjustments will have to be made to image positioning, motion and timing. I think the simplest option is to remove the style that's been applied and do it manually or select an alternative style that actually uses the number of images you want.

If you want to do it manually and need help. Describe the effect you want to end up with we'll see if we can help you get there.

Dick

"It is the mark of an educated mind to be able to entertain a thought without accepting it." Aristotle ((PSG, PSE & Fuji HS20 user)) Presentation Impact Blog

Are you saying the images move across the screen? If that's the case, then the blank area can only be filled if you reposition the remaining 3 images so they're equally spaced--if equal spacing is what you want.

Let's assume the images go from left to right. Working only with horizontal positioning, begin layer 1 at -100 and end it at 200. Layer 2 should start at -150 and end at 150. Layer 3 starts at -200 and ends at 100. If you take a good look at the difference between the starting and ending numbers for all three layers, there's a span of 300 consistently. This will cause them all to move across the screen at the same speed while maintaining the same space in between them.